1. Field of the Invention
This invention relates generally to methods, improved compositions and kits to remediate microfloral and biofilm development on the laundering surfaces of horizontal axis washers which provide a sealed high humidity environment between uses that promulgate the formation, survival and transfer of microbial contaminants within the washer and to treated textile items.
2. Description of the Related Art
Transfer of pathogenic organisms in the laundering process has been documented in the academic and commercial literature. Organisms such as fecal coliforms normally survive the laundering process, in spite of rigorous washing and drying conditions, creating a pathway for the persistence and propagation of this process is the formation of biofilm of the pathogens. Biofilms are a tenacious film of polysaccharides excreted by the pathogens, which form a protective covering to shield the microbes from environmental forces. This film is difficult to remove without mechanical action and/or through the use of aggressive chemicals.
Some users of so-called “High Efficiency” (he) washers have observed that this new class of machines is especially prone to development of biofilm. These machines have been on the market since the mid-1990's; in the last five years the growth of this class has exacerbated a problem which may have always been present, but under-appreciated due to lack of penetration. As numbers of such machines increased on the market, reports increased of musty odors indicative of microbial colonization within the machines. It is possible that a confluence of laundry factors has been responsible for rapid development of this problem: 1. Virtual elimination of phosphates from detergents (which had been widely used until the early 1990s). These agents were very effective at cleaning surfaces, which probably minimized the chances for biofilm development; 2. Gradual, but increasing, lowering of wash temperatures, and 3) Lack of use of sodium hypochlorite bleach in a weekly routine, due in part to reduced wearing of white garments and consumer fears of using this and similar halogen based bleaches in their laundry.
HE washing machine manufacturers have attempted to address this problem to eliminate the biofilms, which they have observed building up on components that are difficult to access for vigorous cleaning, such as the back of the wash drum, and internal pump parts, channels and tubing. The proliferation of pathogens is especially alarming when one understands the nature of the pathogens found in such environments, which may include mold and mildew spores, pathogenic gram negative and gram positive bacteria, and fungus.
Washing machine manufacturers have a recommended approach and method of alleviating the biofilm through introducing approximately three cups of regular household bleach into an empty (non-detergent, no clothes) washload, which is in effect equal to an exposure exceeding about 2500 ppm sodium hypochlorite. While very effective at removing the biofilm, this treatment would potentially lead to corrosion of the metallic parts of the washer after repeating usage, specifically at the weld junctions of the stainless steel portions, as well as the aluminum/copper alloy agitator and parts constructed of susceptible metal alloys and plastics, particularly nylon bushings, bumpers and seals, because commercially available hypochlorite bleaches have no corrosion inhibiting materials present.
Accordingly, there is a need for improved processes and materials for remediation of microfloral and biofilm development on the laundering surfaces of horizontal axis washers to prevent the formation, survival and transfer of microbial contaminants within the washer, which are effective without causing corrosion and degradation of susceptible parts and materials employed in the construction of the machines, and which further provide a convenient and easy to use treatment option for users to address these problems.